I am currently running
1x WD 640 GB drive because when they came out they were very fast (4kb sectors if I remember correctly) (it is my boot drive)
2x WD 1500 GB drives because they were the biggest I could get at the time
3x WD 2000 GB drives because I lost 4TB of data on my 2TB Seagates
Using a custom 6x sata power cable I made for my corsair PSU.
that is using all my 6 internal sata ports
1x WD 2000 GB external passport drive
I am running out of space
probably getting another WD 2000 GB external drive.
all but the 640 GB drives are running ExFAT with 32MB clusters to avoid fragmentation (they store large media files)